Multiple fuse plug



May 16, 1933. n l R, W, Sco-rf' 1,909,94

MULTIPLE FUSE PLUG Filed Aug. 8,' 195o A #02m ey Patented May 16, 1933 UNITED STATES PATENT OFFICE YRAY w. SCOTT, OF Los ANGELES, CALIFORNIA, AssIGNOR To TWINING-SOOTT', INC.,

LTD., OF Los ANGELES, OALIFORNIA, A CORPORATION oF CALIFORNIA MULTIPLE FUSE PLUG Application filed August 8, 1930. Serial No. 473,961. t

This invention relates to an improvement in fuse plugs and more particularly to what is generally termed a multiple fuse'plug; that is, a plug having a plurality oi fuses which can be successively introduced into the electrical circuit'as preceding ones are melted or burned out.

It is an object of this invention to pirovide amultiple fuse plug, the parts of which 3 are all compactly enclosed, thus obviatmg the'possibility of any undesired melting of the fuse elements, due to accidental contact with any external objects.

It is a further object of this invention to E5 provide a multiple fuse plug which is light in weight and simple in design and construction'. y

It is a further object of this invention to provide a multiple fuse plug which is well insulated against any possible short circuiting, and which is inexpensive to manufacture.

My invention; possesses many other advantages, and has other objects which may be made more easily apparent from a consideration of one embodiment of my invention. For this purpose I have shown a form in the drawing accompanying and forming part of the present specification. I shall now proceed to describe this form in detail, which illustrates the general principles of my invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of my invention is best defined by the appended claims.

Referring tol the drawing:

Figure 1 is a vertical section through a multiple fuse plug embodying my invention;

Fig. 2 is a plan view thereof;

Fig.v 3 is a view along the plane 3-3 of Fig. 1; with the parts 25 of element 19 omitted.

Fig. 4 is a detailed section along the plane 1 -4 of Fig. 1 showing a novel means of uniting a plurality of layers; and

Fig. 5 is an enlarged perspective view of a Contact member embodying my invention.

In order to aid in more readily understanding the novel features embodying this invention, the description thereof will closely follow the manner in which the constituent parts are assembled. Thus a supporto ing structure or shell 10 has its sides stamped 55 into the shape of screw threads so that the plug may be readily screwed into a complementary receptacle in the fuse box. The shell 10 is formed at its upper end with an outwardly projecting flange or shoulder 11 which provides a support for a purpose to be hereinafter described. At its lower end, a flange or shoulder 12 extends inwardly, and thereby reduces the size of the axial opening at the bottom of the shell 10. The shell is formed of a rigid metallic material which is self-supporting in order to obviate the need of a porcelain or other insulating iller or base.

A. post 13, formedrof some suitable conducting material, is rigidly maintained in the axial opening of the shell, by means of a pair of bre washers 14, 15 or other insulating material disposed on opposite sides of the shoulder 12. The'post 13 extends 75 through an axial opening in the washers 14., 15, and is maintained in its rigid position by means of a metallic brass retaining washer 16, tightly gripping post 13. The post 13 is formed with an external cap or head 17 which projects beyond the washer 15 in order to provide a means for making an electrical contact in the receptacle, and thereby witha source of electrical potential.

The multiple fuse eiiect is produced by means of a fusible element 18 made of some suitable fuse material. The fuse element 18 is suitably insulated by means of oppositely disposed fibre washers 19, 20 and a micaceous plate 21, and thereby forms what will herein be termed a composite material. An indicating pointer 22 having a depending boss or hub 23 extends through and is rotatable in the axial opening of the composite material. A projecting lug 24 is formed integral with the boss 23 and for a purpose to be hereinafter described.

The fibre washer 19 is readily visible through the micaceous plate 21, and as is readily apparent from Figs. 1, 2 and 3, is formed with a plurality of spaced radial depending ribs 25, struck upwardly from washer 19. A plurality of spaced concentric openings 26 in element 19 aid in insulating the fusible element 18. A pair of oppositely disposed tongues 29 is formed integral with the washer 19 for a purpose to be hereinafter described.

Referring to Fig. 3, it is readily apparent that the fusible element 18 comprises a plurality of vconcentrically spaced segmental portions 26 defining a plurality of spaced radial openings 27 of a size equal to the width of the ribs 25. A circular band 28 of the .fusible material is connected to the segmental portions 26 by means of constrictions 28. It is these constricting portions 28 which melt or burn out when the fuse blows. The width or other dimensions of these constrictions 28 may be varied to suit the amperage which the fuse plug is designed to carry, and varies directly as the current. That is, a larger current will require a greater width or cross section. A

air of oppositely disposed tongues 29 is fbrmed integral with the ring 28 for a purpose to be hereinafter described.

The washer 20 has a diameter of a size considerably smaller than the diameter of the washer 19 or the fusible element 18. A

lurality of spaced radial notches 30 is formed about the outer periphery of the washer 20, (see Fig. 4) for a purpose to be hereinafter described.

To assemble this composite material, the indicating pointer 22 is held in an inverted position with the boss 23 extending upwardy. The micaceous plate 21 is {irst inserted on the boss 23 and the washer 19 placed on the late 21 with the ribs 25 extending upwardly. The fusible element 18 is then placed onto the washer 19 so that the openings 27 are forced over the ribs 25, and thereby lockin the fusible element 18 to the washer 19. he washer 20 is then placed on the fusible element 18 so that the notches 30 engage the ribs 25 in a manner clearly apparent from Figs. 1 and 4. The lug 24, which is square, is then inserted through a square opening 31 of a contact member, referred to as a whole as by 32, (Fig. 5), and is retained on the lug 24 as by the turned up edges 33 of the lug 24.

The opening 31 coincides with the contour of lug 24 and is accordingly rotatable therewith. The contact element 32 comprises a plate portion 34 having an upwardly raised bridge portion 35, at one edge, which is adapted to contact with the segmental portions 26 of the fusible element 18. At its opposite edge, an arm 36 extends downwardly and merges into an integral U-shaped member 37. The legs comprising the U-shaped member are spaced apart of a width adapted to partly embrace the post 13.

The indicating pointer 22, the composite structure, and the contact element 32 are inverted and placed on the supporting ledge or shoulder 11 of the shell 10 in a manner clearly shown in Fig. 1. It is readily apparent from this figure that the contact ortion 35 extends beyond the periphery o the washer 20 and is flexed upwardly. The plate 34 is formed of a spring-like material which insures the intimate contact of the contacting portion 35 with the segmental portions 26 of the element 18.

During the assembly of the composite material, the tongue portions 29', 29 and 29, 29 of the washer 19 and the fusible element 18 respectively, are aligned, one with the other. In this manner, the composite material is keyed to an insulating ring 38 by means of corresponding grooves 39 formed therein. The insulating material 38 is formed with a ledge 40 of a size equal to the ledge 11 and adapted to fit thereunder. A downwardly extending side 41 contacts with a side of the shell 10 and a downwardly extending side 42 of cap 43 acts to confine the composite material in its assembled p0si tion. A metal cap 43 intimatel maintains the composite material on the l ge 11. The cap 43 is formed of brass or other metallic material and is bent over the edge of the micaceous plate 21 and at 44 is bent under a shoulder of the insulating 'portion 38, and thereby maintains the intimate contact of the composite material with the shoulder 11.

The operation of the fuse plug is now readily apparent from the fore oing. The indicator 22 with its depending oss 23 and lug 24 is rotatable with respect to the composite material. The circuit is completed by means of the cap 17 bein brought in contact with the receptacle, t e current flowing upwardly through the st 13 to the U-shaped member 37 and nally to the fuse element 18 through the medium of the contact portion 35; and thence to shell 10. As the fuses 28 melt or burn out, contact between a segment 26' and a contact portion 35 is made by simply changing the radial position of the indicating pointer 22.

I claim:

1. In a multiple fuse plug, a fusible element having a series of inwardly directed members, means for supportin said element both at the outer edge and at te inner edges of the members, means for conducting curgoo rent successively through these members, including a central conducting post, and a contact member slidably contacting with the post and arranged successively to engage said members.

2. A fuse plug comprising a rigid supporting structure, a contact member and a means retained by said supporting structure to conduct electrical energy to the contact member, a fusible element, an indicator having a boss extending through and rotatable in the fusible element, said contact member slidably engaging the fusible element and frictionally retained by and rotatable with the indicator whereby a movement of the indicator will produce a corresponding movement of the contact member over the fusible element.

3. A fuse plug comprising a rigid supporting structure, a contact member, and a means retained by said supporting structure to conduct electrical energy to the contact member, a fusible element comprising a plurality of spaced segmental portions, an indicator having a boss extending through and rotatable in the fusible element, said contact member rotating with the indicator and slidably engaging the segmental portions of the fusible element whereby a movement of the indicator will produce a corresponding movement of the contact member over the successive segmental portions.

4. A fuse plug comprising a rigid supporting structure, a contact member, and a post rigidly retained by said supporting structure to conduct electrical energy to the contact member, a fusible element comprising a plurality of spaced concentric segmental portions, anv insulating material having spaced ribs extending through the spaces defined by said segmental portions, to form a composite material, an indicator having a boss extending through and rotatable in the composite material, said contact member being secured to and rotating with the indicator and slidably engaging the segmental portions whereby a movement of the indicator will produce a corresponding movement of the contact member over the successive segmental portions, and means retaining said composite material on said boss.

5. A fuse plug comprising a rigid supporting structure, a contact member, and a post rigidly retained by said supporting structure to conduct electrical energy to the contact member, a fusible element comprising a plurality of spaced concentric segmental portions, an insulating material having spaced ribs extending through the spaces defined by said segmental portions and into spaced notches about the peripheral edge of an insulating material in order to lock the fusible element between the insulating materials and thereby form a composite product, an indicator having a boss, the boss on the indicator extending through and rotatable in the composite material, said contact member being secured to and rotating with the indicator and slidably engaging the segmental portions whereby a movement of the indicator will produce a corresponding movement of the contact member over the successive segmental portions, and means Eetaining said composite material on said oss.

In testimony whereof, I have subscribed my name.

RAY W. SCOTT. 

